Known hand-held computing devices, designed to be operated by one hand, suffer several shortcomings. One of the shortcomings is that the individual keys are usually small and difficult to access, even with an anatomically small hand. Further, the control keys are numerous and the use of these devices is difficult to learn.
In addition, usually, the devices are of a flat rectangular shape with the rows of keys extending parallel to the top and bottom edges of the external shape. The legends on the keys are also printed in a vertical orientation with respect to the top and bottom edges of the device. If the user of the device holds the device in their left hand and positions the device so the top and bottom axes are parallel to a frontal plane of the body, then the right hand, to access the keys of the device, has to be ulnar-deviated outwardly to have the fingers effectively access the keys.
Alternately, if the user chooses to posture the device at an angle that would eliminate the ulnar-deviation of the hand, then the visual appearance to the users eye is skewed away from a primary reading position. The key legends and the screen are thereby stressfully oriented away from both the horizontal and vertical planes.
Further, these known devices typically make no provision for the thumb to be actively involved in accessing the keys. Since all the keys are in the same plane, the thumb would have to access these keys in a non-prehensile manner. This is awkward and contrary to a prehensile mode wherein the anatomically opposable thumb moves naturally towards the fingers.